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growth
Abstract: Douglas fir (Pseudotsuga menziesii) seedlings planted on areas receiving one of
four site preparation treatments (scarify, scarify/till, soil removal, and soil removal/till) and on
unprepared control areas were compared for 5 yr at a high-altitude, nutrient-poor site in the
western Siskiyou Mountains. Fifth-year survival of seedlings was at least 85% among machineprepared
plots, compared to 42% on control plots. Cover of competing vegetation remained less
than 25% during the period for all machine treatments. In contrast, vegetation cover on control
plots was 30% at the time of planting and increased to nearly 75% after 5 yr. Competing
vegetation clearly impeded seedling performance. The effects of unusually droughty conditions at
the time of planting in 1982 were examined further by interplanting additional seedlings in the
soil-removal treatment in 1985. The interplanting was followed by more normal spring
precipitation, and seedlings grew better over 5 yr than those planted in 1982. The slow recovery
of competing vegetation and generally poor seedling growth on all treatments during both
planting years are attributed to low soil fertility.
384. Messier, C. and A.K. Mitchell. 1994. Effects of thinning in a 43-year-old Douglas-fir stand on
above- and below-ground biomass allocation and leaf structure of understory Gaultheria shallon.
Forest-Ecology-and-Management 68(2/3): 263-271.
Keywords: thinning
stand conditions
Abstract: Salal (Gaultheria shallon) was studied in an unthinned and a heavily thinned
(two-thirds of basal area removed) 43-yr-old Douglas fir (Pseudotsuga menziesii) plot 6 yr after
thinning at Shawnigan Lake on southern Vancouver Island, British Columbia. The increase in
both above- and below-ground resources caused by thinning resulted in a smaller fine-root/leaf
biomass ratio in the thinned (1.2) than the unthinned (2.0) plot. The balance between the
production of fine-roots to acquire limited water and of foliage to acquire limited light is
suggested as an explanation for this shift in carbon allocation from fine-root to leaf biomass
between the two plots. The responses of G. shallon to thinning are discussed in relation to its role
as a competitor for below-ground resources.
385. Mikels, R.A. 1983. Melamine, a controlled release fertilizer for conifer seedlings. Forestry-
Abstracts 44(11): 698.
Keywords: fertilization
growth
386. Miller, G.E. 1983a. Evaluation of the effectiveness of cold-water misting of trees in seed orchards
for control of Douglas-fir cone gall midge (Diptera: Cecidomyiidae). Journal-of-Economic-
Entomology 76(4): 916-919.
Keywords: seed orchard management
tree/stand protection
tree/stand health
tree phenology
Abstract: The effectiveness of misting trees with cold water in delaying reproductive bud
burst of Douglas fir (Pseudotsuga menziesii) and consequently controlling Contarinia oregonensis
Foote was evaluated in tests in seed orchards in British Columbia in 1978-80. The misting